Question about bilateral switch ICs?

Question

I'm using an HC4066B Bilateral Switch with a user interface for an application (I got a big bag of the for a terrific deal), but the signal that I'm trying to control with a control gate is open even when the control is low! Putting the control high (and by control I mean gate) increases the strength of the signal by a small amount, but when its low the gate is still open and I actually have to ground the control pin to close the gate. Any help?

Answer 1

you are suppose to ground it to close the gate. so it is working correctly. your signal needs to be a 0v or 5v signal. when you remove  the 5v you are not applying ground, you are just letting it float. it is most likely an open collector style TTL. which means the current will flow out of the pin when it is off. you must give it somewhere to go. place a 4.7k ohm resistor between the gate and ground (there will be 3 connections, the pin the 5v source and the resistor). when the 5v signal is removed, the gate can see ground through the resistor.

Answer 2

The question was confusing to read but it looks like you are saying that you have one of the switch outputs floating, right? You need to tie the switch outputs to ground through some resistance in order to force it to go low when the 4066 switch is open. How much resistance depends on your application.